{"id":5167,"date":"2026-03-11T08:37:00","date_gmt":"2026-03-11T00:37:00","guid":{"rendered":"https:\/\/www.topfastpcb.com\/?p=5167"},"modified":"2026-03-05T11:30:56","modified_gmt":"2026-03-05T03:30:56","slug":"pcb-trace-width-current-capacity-guide","status":"publish","type":"post","link":"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/","title":{"rendered":"PCB Trace Width vs Current Capacity: K\u00e4yt\u00e4nn\u00f6n suunnitteluopas"},"content":{"rendered":"<p>Oikean levyisten PCB-j\u00e4lkien suunnittelu on t\u00e4rke\u00e4\u00e4, jotta voidaan <strong>s\u00e4hk\u00f6inen luotettavuus, l\u00e4mm\u00f6nkest\u00e4vyys ja valmistettavuus<\/strong>.<\/p><p>Jos johdin on liian kapea sen kuljettamaan virtaan n\u00e4hden, se voi aiheuttaa:<\/p><ul class=\"wp-block-list\"><li>Liiallinen kuumuus<\/li>\n\n<li>J\u00e4nniteh\u00e4vi\u00f6<\/li>\n\n<li>Signaalin eheysongelmat<\/li>\n\n<li>PCB-vika \u00e4\u00e4ritapauksissa<\/li><\/ul><p>Ymm\u00e4rt\u00e4\u00e4, miten <strong>j\u00e4ljen leveys liittyy virran kapasiteettiin<\/strong> auttaa insin\u00f6\u00f6rej\u00e4 suunnittelemaan levyt, jotka t\u00e4ytt\u00e4v\u00e4t sek\u00e4 <strong>s\u00e4hk\u00f6iset vaatimukset ja valmistusrajoitukset<\/strong>.<\/p><p>T\u00e4ss\u00e4 artikkelissa selitet\u00e4\u00e4n, miten j\u00e4ljen leveys toimii, miten arvioida nykyinen kapasiteetti ja miten optimoida asettelut reaalimaailman piirilevyn valmistusta varten.<\/p><div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"600\" height=\"337\" src=\"https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width.jpg\" alt=\"PCB J\u00e4ljen leveys\" class=\"wp-image-5168\" srcset=\"https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width.jpg 600w, https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-300x169.jpg 300w, https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-18x10.jpg 18w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><\/figure><\/div><div id=\"ez-toc-container\" class=\"ez-toc-v2_0_74 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Sis\u00e4llysluettelo<\/p>\n<span class=\"ez-toc-title-toggle\"><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Why_Trace_Width_Matters_in_PCB_Design\" >Miksi j\u00e4ljen leveys on t\u00e4rke\u00e4\u00e4 PCB-suunnittelussa<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Copper_thickness\" >Kuparin paksuus<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Temperature_rise\" >L\u00e4mp\u00f6tilan nousu<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#External_vs_internal_layers\" >Ulkoiset ja sis\u00e4iset kerrokset<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Basic_Trace_Width_and_Current_Relationship\" >Perusj\u00e4ljen leveyden ja virran suhde<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Internal_vs_External_Trace_Capacity\" >Sis\u00e4inen vs. ulkoinen j\u00e4ljityskapasiteetti<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#External_layers\" >Ulkoiset kerrokset<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Internal_layers\" >Sis\u00e4iset kerrokset<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Thermal_Effects_of_Narrow_Traces\" >Kapeiden j\u00e4lkien l\u00e4mp\u00f6vaikutukset<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Copper_overheating\" >Kuparin ylikuumeneminen<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Laminate_degradation\" >Laminaatin hajoaminen<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Solder_joint_reliability_issues\" >Juotosliitosten luotettavuusongelmat<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#How_to_Calculate_PCB_Trace_Width_Step-by-Step\" >Kuinka laskea PCB Trace Width (askel askeleelta)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Step_1_%E2%80%93_Determine_maximum_current\" >Vaihe 1 - M\u00e4\u00e4rit\u00e4 enimm\u00e4isvirta<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Step_2_%E2%80%93_Define_allowable_temperature_rise\" >Vaihe 2 - M\u00e4\u00e4rit\u00e4 sallittu l\u00e4mp\u00f6tilan nousu<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Step_3_%E2%80%93_Choose_copper_thickness\" >Vaihe 3 - Valitse kuparin paksuus<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Step_4_%E2%80%93_Use_a_trace_width_calculator\" >Vaihe 4 - K\u00e4yt\u00e4 j\u00e4ljen leveyden laskuria<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Step_5_%E2%80%93_Validate_using_DFM_review\" >Vaihe 5 - Validointi DFM-arvioinnin avulla<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Practical_Design_Tips_for_High-Current_Traces\" >K\u00e4yt\u00e4nn\u00f6n suunnitteluvinkkej\u00e4 suurvirtaisia j\u00e4lki\u00e4 varten<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Increase_copper_thickness\" >Kuparin paksuuden lis\u00e4\u00e4minen<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Use_wider_copper_pours\" >Laajemmat kuparikaadot<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Add_parallel_traces\" >Lis\u00e4\u00e4 rinnakkaisia j\u00e4lki\u00e4<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Use_thermal_vias\" >K\u00e4yt\u00e4 termisi\u00e4 l\u00e4pivientej\u00e4<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Manufacturing_Constraints_for_Trace_Width\" >J\u00e4ljen leveyden valmistusrajoitukset<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#How_Manufacturers_Evaluate_Trace_Design\" >Miten valmistajat arvioivat j\u00e4ljityssuunnittelua<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#Conclusion\" >P\u00e4\u00e4telm\u00e4<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/#FAQ\" >FAQ<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Why_Trace_Width_Matters_in_PCB_Design\"><\/span>Miksi j\u00e4ljen leveys on t\u00e4rke\u00e4\u00e4 PCB-suunnittelussa<span class=\"ez-toc-section-end\"><\/span><\/h2><p>J\u00e4ljen leveys m\u00e4\u00e4ritt\u00e4\u00e4, kuinka paljon virtaa kuparijohdin voi turvallisesti kuljettaa ilman ylikuumenemista.<\/p><p>Suhteeseen vaikuttavat useat tekij\u00e4t:<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Copper_thickness\"><\/span>Kuparin paksuus<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Yleisi\u00e4 arvoja ovat:<\/p><ul class=\"wp-block-list\"><li>1 oz kuparia (35 \u00b5m)<\/li>\n\n<li>2 oz kuparia (70 \u00b5m)<\/li>\n\n<li>Raskaat kuparimallit (3 oz+)<\/li><\/ul><p>Paksumpi kupari lis\u00e4\u00e4 virtakapasiteettia.<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Temperature_rise\"><\/span>L\u00e4mp\u00f6tilan nousu<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Suunnitteluohjeissa oletetaan yleens\u00e4 hyv\u00e4ksytt\u00e4v\u00e4 l\u00e4mp\u00f6tilan nousu, kuten:<\/p><ul class=\"wp-block-list\"><li>10\u00b0C<\/li>\n\n<li>20\u00b0C<\/li>\n\n<li>30\u00b0C<\/li><\/ul><p>Alhaisempi l\u00e4mp\u00f6tilan nousu edellytt\u00e4\u00e4 leve\u00e4mpi\u00e4 j\u00e4lki\u00e4.<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"External_vs_internal_layers\"><\/span>Ulkoiset ja sis\u00e4iset kerrokset<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Ulkoiset kerrokset haihduttavat l\u00e4mp\u00f6\u00e4 helpommin.<\/p><p>Tyypillinen s\u00e4\u00e4nt\u00f6:<\/p><ul class=\"wp-block-list\"><li>Sis\u00e4iset j\u00e4ljet kuljettavat <strong>v\u00e4hemm\u00e4n virtaa<\/strong> kuin ulomman kerroksen j\u00e4ljet.<\/li><\/ul><p>Valmistukseen liittyv\u00e4t n\u00e4k\u00f6kohdat, kuten kuparin paksuus ja kerrosten pinoaminen, selitet\u00e4\u00e4n PCB-tuotannon ty\u00f6nkulussa osoitteessa: <strong><a href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-manufacturing-process-explained-step-by-step\/\">PCB valmistusprosessi selitetty askel askeleelta<\/a><\/strong><\/p><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Basic_Trace_Width_and_Current_Relationship\"><\/span>Perusj\u00e4ljen leveyden ja virran suhde<span class=\"ez-toc-section-end\"><\/span><\/h2><p>Virran ja j\u00e4ljen leveyden v\u00e4list\u00e4 suhdetta arvioidaan tyypillisesti k\u00e4ytt\u00e4m\u00e4ll\u00e4 arvoa <strong>IPC-2221-standardi<\/strong>.<\/p><p>Yksinkertaistettu nyrkkis\u00e4\u00e4nt\u00f6:<\/p><figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>J\u00e4ljen leveysN\/OFF)<\/th><th>Kupari Paino<\/th><th>Nykyinen kapasiteetti<\/th><\/tr><\/thead><tbody><tr><td>10 miljoonaa<\/td><td>1 oz<\/td><td>~1 A<\/td><\/tr><tr><td>20 miljoonaa<\/td><td>1 oz<\/td><td>~2-3 A<\/td><\/tr><tr><td>50 miljoonaa<\/td><td>1 oz<\/td><td>~5-6 A<\/td><\/tr><\/tbody><\/table><\/figure><p>N\u00e4m\u00e4 ovat <strong>likim\u00e4\u00e4r\u00e4iset arvot<\/strong>, ja tarkkoihin laskelmiin olisi sis\u00e4llytt\u00e4v\u00e4:<\/p><ul class=\"wp-block-list\"><li>l\u00e4mp\u00f6tilan nousu<\/li>\n\n<li>kuparin paksuus<\/li>\n\n<li>j\u00e4ljen pituus<\/li>\n\n<li>hallitusymp\u00e4rist\u00f6<\/li><\/ul><p>Virran ep\u00e4asianmukainen k\u00e4sittely on yksi yleisimmist\u00e4 syist\u00e4, joista keskustellaan kohdassa: <strong><a href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/common-pcb-failures-causes-solutions\/\">Yleiset PCB-viat: PCB PCB-piirilevyt: Syyt ja ratkaisut<\/a><\/strong><\/p><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Internal_vs_External_Trace_Capacity\"><\/span>Sis\u00e4inen vs. ulkoinen j\u00e4ljityskapasiteetti<span class=\"ez-toc-section-end\"><\/span><\/h2><p>Piirilevyjen pinoutuminen vaikuttaa l\u00e4mp\u00f6suorituskykyyn.<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"External_layers\"><\/span>Ulkoiset kerrokset<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Edut:<\/p><ul class=\"wp-block-list\"><li>parempi l\u00e4mm\u00f6ntuotto<\/li>\n\n<li>suurempi virtakapasiteetti<\/li>\n\n<li>helpompi tarkastus<\/li><\/ul><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Internal_layers\"><\/span>Sis\u00e4iset kerrokset<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Rajoitukset:<\/p><ul class=\"wp-block-list\"><li>loukkuun j\u00e4\u00e4nyt l\u00e4mp\u00f6<\/li>\n\n<li>v\u00e4hentynyt j\u00e4\u00e4hdytys<\/li>\n\n<li>pienempi virrankapasiteetti<\/li><\/ul><p>Esimerkiksi:<\/p><figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Kerrostyyppi<\/th><th>Nykyinen kapasiteetti<\/th><\/tr><\/thead><tbody><tr><td>Ulkoinen<\/td><td>Korkeampi<\/td><\/tr><tr><td>Sis\u00e4inen<\/td><td>50-70% ulkoisen<\/td><\/tr><\/tbody><\/table><\/figure><p>Kerrossuunnittelu vaikuttaa my\u00f6s valmistuksen monimutkaisuuteen, jota k\u00e4sitell\u00e4\u00e4n kohdassa <strong><a href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/8-layer-pcb-stackup\/\">PCB Layer Stackup Design Guide -suunnitteluopas<\/a><\/strong><\/p><div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"600\" height=\"337\" src=\"https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-1.jpg\" alt=\"PCB J\u00e4ljen leveys\" class=\"wp-image-5169\" srcset=\"https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-1.jpg 600w, https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-1-300x169.jpg 300w, https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-1-18x10.jpg 18w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><\/figure><\/div><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Thermal_Effects_of_Narrow_Traces\"><\/span>Kapeiden j\u00e4lkien l\u00e4mp\u00f6vaikutukset<span class=\"ez-toc-section-end\"><\/span><\/h2><p>Jos j\u00e4ljet ovat alimitoitettuja, l\u00e4mm\u00f6n kertymisest\u00e4 tulee vakava riski.<\/p><p>Mahdollisia seurauksia ovat:<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Copper_overheating\"><\/span>Kuparin ylikuumeneminen<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Suuri virrantiheys voi nostaa kuparin l\u00e4mp\u00f6tilaa nopeasti.<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Laminate_degradation\"><\/span>Laminaatin hajoaminen<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Liiallinen kuumuus voi vahingoittaa piirilevyn alustaa.<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Solder_joint_reliability_issues\"><\/span>Juotosliitosten luotettavuusongelmat<span class=\"ez-toc-section-end\"><\/span><\/h3><p>L\u00e4mp\u00f6kierto rasittaa komponentteja ja tyynyj\u00e4.<\/p><p>Monet luotettavuusongelmat johtuvat s\u00e4hk\u00f6- ja l\u00e4mp\u00f6suunnitteluun liittyvist\u00e4 ongelmista. Voit lukea lis\u00e4\u00e4 osoitteessa: <strong><a href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-reliability-testing-standards\/\">PCB:n luotettavuuden testausmenetelm\u00e4t selitettyin\u00e4<\/a><\/strong><\/p><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"How_to_Calculate_PCB_Trace_Width_Step-by-Step\"><\/span>Kuinka laskea PCB Trace Width (askel askeleelta)<span class=\"ez-toc-section-end\"><\/span><\/h2><p>Suunnittelijat k\u00e4ytt\u00e4v\u00e4t usein laskureita tai IPC-standardeista johdettuja kaavoja.<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Step_1_%E2%80%93_Determine_maximum_current\"><\/span>Vaihe 1 - M\u00e4\u00e4rit\u00e4 enimm\u00e4isvirta<span class=\"ez-toc-section-end\"><\/span><\/h3><p>M\u00e4\u00e4rit\u00e4 suurin virta, joka johtimen on kestett\u00e4v\u00e4.<\/p><p>Esimerkki:<\/p><pre class=\"wp-block-preformatted\">Moottorinohjaimen l\u00e4ht\u00f6 = 4 A<\/pre><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Step_2_%E2%80%93_Define_allowable_temperature_rise\"><\/span>Vaihe 2 - M\u00e4\u00e4rit\u00e4 sallittu l\u00e4mp\u00f6tilan nousu<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Tyypilliset arvot:<\/p><pre class=\"wp-block-preformatted\">10\u00b0C konservatiivinen suunnittelu<br>20 \u00b0C:n yleinen rakenne<\/pre><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Step_3_%E2%80%93_Choose_copper_thickness\"><\/span>Vaihe 3 - Valitse kuparin paksuus<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Esimerkki:<\/p><pre class=\"wp-block-preformatted\">1 oz kuparia<\/pre><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Step_4_%E2%80%93_Use_a_trace_width_calculator\"><\/span>Vaihe 4 - K\u00e4yt\u00e4 j\u00e4ljen leveyden laskuria<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Monet EDA-ty\u00f6kalut tai verkkolaskimet antavat tarkkoja arvoja.<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Step_5_%E2%80%93_Validate_using_DFM_review\"><\/span>Vaihe 5 - Validointi DFM-arvioinnin avulla<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Valmistajat voivat varmistaa, ett\u00e4 malli t\u00e4ytt\u00e4\u00e4 valmistustoleranssit.<\/p><p>DFM-tarkastusmenetelm\u00e4t selitet\u00e4\u00e4n seuraavassa: <strong><a href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/complete-guide-to-pcb-design-for-manufacturability-dfm\/\">Mik\u00e4 on PCB DFM ja miksi sill\u00e4 on merkityst\u00e4 valmistuksessa?<\/a><\/strong><\/p><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Practical_Design_Tips_for_High-Current_Traces\"><\/span>K\u00e4yt\u00e4nn\u00f6n suunnitteluvinkkej\u00e4 suurvirtaisia j\u00e4lki\u00e4 varten<span class=\"ez-toc-section-end\"><\/span><\/h2><p>Virran k\u00e4sittely\u00e4 voidaan parantaa useilla tekniikoilla.<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Increase_copper_thickness\"><\/span>Kuparin paksuuden lis\u00e4\u00e4minen<span class=\"ez-toc-section-end\"><\/span><\/h3><p>K\u00e4ytt\u00e4m\u00e4ll\u00e4 <strong>2 oz kuparia<\/strong> parantaa merkitt\u00e4v\u00e4sti nykyist\u00e4 kapasiteettia.<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Use_wider_copper_pours\"><\/span>Laajemmat kuparikaadot<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Suuret kuparialueet v\u00e4hent\u00e4v\u00e4t vastusta ja l\u00e4mp\u00f6\u00e4.<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Add_parallel_traces\"><\/span>Lis\u00e4\u00e4 rinnakkaisia j\u00e4lki\u00e4<span class=\"ez-toc-section-end\"><\/span><\/h3><p>Virran jakaminen useammalle johtimelle v\u00e4hent\u00e4\u00e4 kuormitusta.<\/p><h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Use_thermal_vias\"><\/span>K\u00e4yt\u00e4 termisi\u00e4 l\u00e4pivientej\u00e4<span class=\"ez-toc-section-end\"><\/span><\/h3><p>L\u00e4mp\u00f6l\u00e4piviennit jakavat l\u00e4mp\u00f6\u00e4 kerrosten v\u00e4lill\u00e4.<\/p><p>Poraus ja valmistuksen kautta tapahtuva valmistus on k\u00e4sitelty kohdassa: <strong><a href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-drilling-vs-laser-drilling\/\">PCB-poraus vs. laserporaus: Erilaiset valmistustavat: Valmistuserot<\/a><\/strong><\/p><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Manufacturing_Constraints_for_Trace_Width\"><\/span>J\u00e4ljen leveyden valmistusrajoitukset<span class=\"ez-toc-section-end\"><\/span><\/h2><p>Piirilevyjen valmistus asettaa k\u00e4yt\u00e4nn\u00f6n rajoituksia.<\/p><p>Tyypilliset valmistusvalmiudet:<\/p><figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Parametri<\/th><th>Tyypillinen arvo<\/th><\/tr><\/thead><tbody><tr><td>V\u00e4himm\u00e4isj\u00e4ljen leveys<\/td><td>4-6 miljoonaa<\/td><\/tr><tr><td>V\u00e4himm\u00e4isv\u00e4li<\/td><td>4-6 miljoonaa<\/td><\/tr><tr><td>Raskaat kuparimallit<\/td><td>erityinen prosessi<\/td><\/tr><\/tbody><\/table><\/figure><p>Suunnittelu valmistusrajojen puitteissa parantaa tuotosta ja alentaa kustannuksia.<\/p><p>Suunnittelun monimutkaisuuden ja tuotantokustannusten v\u00e4list\u00e4 suhdetta k\u00e4sitell\u00e4\u00e4n seuraavassa: <strong><a href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/how-to-reduce-pcb-cost-without-compromising-quality\/\">Kuinka v\u00e4hent\u00e4\u00e4 PCB-kustannuksia laatua tinkim\u00e4tt\u00e4 laadusta<\/a><\/strong><\/p><div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"600\" height=\"337\" src=\"https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-2.jpg\" alt=\"PCB J\u00e4ljen leveys\" class=\"wp-image-5170\" srcset=\"https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-2.jpg 600w, https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-2-300x169.jpg 300w, https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-2-18x10.jpg 18w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><\/figure><\/div><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"How_Manufacturers_Evaluate_Trace_Design\"><\/span>Miten valmistajat arvioivat j\u00e4ljityssuunnittelua<span class=\"ez-toc-section-end\"><\/span><\/h2><p>Ammattimaiset PCB-valmistajat suorittavat yleens\u00e4 <strong>suunnittelus\u00e4\u00e4nt\u00f6jen tarkastukset (DRC)<\/strong> ja <strong>DFM-analyysi<\/strong> ennen tuotantoa.<\/p><p>He tarkastelevat:<\/p><ul class=\"wp-block-list\"><li>j\u00e4ljen leveys vs. kuparin paino<\/li>\n\n<li>et\u00e4isyystoleranssit<\/li>\n\n<li>l\u00e4mp\u00f6jakauma<\/li>\n\n<li>virransietokyky<\/li><\/ul><p>Sellaisissa yrityksiss\u00e4 kuin <strong>TOPFAST<\/strong>, insin\u00f6\u00f6rit tarkistavat usein layout-parametrit ennen valmistuksen aloittamista v\u00e4hent\u00e4\u00e4kseen valmistusriskej\u00e4 ja varmistaakseen vakaan suorituskyvyn kaikissa tuotantoeriss\u00e4.<\/p><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Conclusion\"><\/span>P\u00e4\u00e4telm\u00e4<span class=\"ez-toc-section-end\"><\/span><\/h2><p>J\u00e4ljen leveydell\u00e4 on kriittinen rooli piirilevyn s\u00e4hk\u00f6isen luotettavuuden ja valmistettavuuden kannalta.<\/p><p>Keskeisi\u00e4 otteita ovat muun muassa:<\/p><ul class=\"wp-block-list\"><li>J\u00e4ljen leveys m\u00e4\u00e4ritt\u00e4\u00e4 virtakapasiteetin ja l\u00e4mp\u00f6tehokkuuden.<\/li>\n\n<li>Kuparin paksuus ja l\u00e4mp\u00f6tilan nousu vaikuttavat voimakkaasti suunnittelus\u00e4\u00e4nt\u00f6ihin.<\/li>\n\n<li>Ulkoiset kerrokset voivat kuljettaa enemm\u00e4n virtaa kuin sis\u00e4iset kerrokset<\/li>\n\n<li>Asianmukainen DFM-arviointi varmistaa, ett\u00e4 mallit voidaan valmistaa luotettavasti.<\/li><\/ul><p>Yhdist\u00e4m\u00e4ll\u00e4 <strong>tarkat virtalaskelmat valmistustietoisten layout-k\u00e4yt\u00e4nt\u00f6jen avulla<\/strong>, insin\u00f6\u00f6rit voivat rakentaa piirilevyj\u00e4, jotka ovat sek\u00e4 s\u00e4hk\u00f6isesti vakaita ett\u00e4 tuotantokelpoisia.<\/p><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"FAQ\"><\/span>FAQ<span class=\"ez-toc-section-end\"><\/span><\/h2><div class=\"schema-faq wp-block-yoast-faq-block\"><div class=\"schema-faq-section\" id=\"faq-question-1772680378958\"><strong class=\"schema-faq-question\">K: Kuinka paljon virtaa piirilevyn j\u00e4lki voi kantaa?<\/strong> <p class=\"schema-faq-answer\">V: Virran kapasiteetti riippuu johtimen leveydest\u00e4, kuparin paksuudesta ja sallitusta l\u00e4mp\u00f6tilan noususta. Esimerkiksi 20 millimetrin j\u00e4lki, jossa on 1 oz kuparia, voi tyypillisiss\u00e4 olosuhteissa kantaa noin 2-3 A.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1772680390686\"><strong class=\"schema-faq-question\">K: Mit\u00e4 tapahtuu, jos piirilevyn j\u00e4lki on liian kapea?<\/strong> <p class=\"schema-faq-answer\">A: Kapea j\u00e4lki voi ylikuumentua, mik\u00e4 aiheuttaa liian suuren resistanssin, j\u00e4nniteh\u00e4vi\u00f6n ja mahdollisia kuparivaurioita.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1772680411563\"><strong class=\"schema-faq-question\">K: Miten lasken PCB-j\u00e4ljen leveyden?<\/strong> <p class=\"schema-faq-answer\">V: Suunnittelijat k\u00e4ytt\u00e4v\u00e4t yleens\u00e4 IPC-2221-pohjaisia laskureita, joissa otetaan huomioon virta, kuparin paksuus ja l\u00e4mp\u00f6tilan nousu.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1772680424687\"><strong class=\"schema-faq-question\">K: Ovatko sis\u00e4iset piirilevyn j\u00e4ljet heikompia kuin ulkoiset?<\/strong> <p class=\"schema-faq-answer\">V: Kyll\u00e4. Sis\u00e4iset j\u00e4ljet kuljettavat yleens\u00e4 v\u00e4hemm\u00e4n virtaa, koska ne haihduttavat l\u00e4mp\u00f6\u00e4 v\u00e4hemm\u00e4n tehokkaasti kuin ulkokerroksen j\u00e4ljet.<\/p> <\/div> <\/div>","protected":false},"excerpt":{"rendered":"<p>T\u00e4ss\u00e4 oppaassa tarkastellaan, miten piirilevyn j\u00e4ljen leveys vaikuttaa virtakapasiteettiin, l\u00e4mm\u00f6nhallintaan ja piirin luotettavuuteen. Se kattaa keskeiset laskentamenetelm\u00e4t, standardisuunnittelus\u00e4\u00e4nn\u00f6t ja DFM:n parhaat k\u00e4yt\u00e4nn\u00f6t, joilla varmistetaan optimaalinen suorituskyky ja valmistettavuus piirilevyjen valmistuksessa.<\/p>","protected":false},"author":1,"featured_media":5171,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[108],"tags":[444],"class_list":["post-5167","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","tag-pcb-trace-width"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v25.1 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>PCB Trace Width vs Current Capacity: Design Guide for Reliable Manufacturing<\/title>\n<meta name=\"description\" content=\"Learn how PCB trace width affects current capacity, heat dissipation, and reliability. This guide explains calculation methods, design rules, and DFM best practices for PCB manufacturing.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/\" \/>\n<meta property=\"og:locale\" content=\"fi_FI\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"PCB Trace Width vs Current Capacity: Design Guide for Reliable Manufacturing\" \/>\n<meta property=\"og:description\" content=\"Learn how PCB trace width affects current capacity, heat dissipation, and reliability. This guide explains calculation methods, design rules, and DFM best practices for PCB manufacturing.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.topfastpcb.com\/fi\/blog\/pcb-trace-width-current-capacity-guide\/\" \/>\n<meta property=\"og:site_name\" content=\"Topfastpcb\" \/>\n<meta property=\"article:published_time\" content=\"2026-03-11T00:37:00+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-3.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"600\" \/>\n\t<meta property=\"og:image:height\" content=\"337\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"\u6258\u666e\u6cd5\u65af\u7279\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Kirjoittanut\" \/>\n\t<meta name=\"twitter:data1\" content=\"\u6258\u666e\u6cd5\u65af\u7279\" \/>\n\t<meta name=\"twitter:label2\" content=\"Arvioitu lukuaika\" \/>\n\t<meta name=\"twitter:data2\" content=\"5 minuuttia\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.topfastpcb.com\/blog\/pcb-trace-width-current-capacity-guide\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.topfastpcb.com\/blog\/pcb-trace-width-current-capacity-guide\/\"},\"author\":{\"name\":\"\u6258\u666e\u6cd5\u65af\u7279\",\"@id\":\"https:\/\/www.topfastpcb.com\/#\/schema\/person\/39870874f1c329f3cd3693593dbdce3a\"},\"headline\":\"PCB Trace Width vs Current Capacity: A Practical Design Guide\",\"datePublished\":\"2026-03-11T00:37:00+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.topfastpcb.com\/blog\/pcb-trace-width-current-capacity-guide\/\"},\"wordCount\":857,\"publisher\":{\"@id\":\"https:\/\/www.topfastpcb.com\/#organization\"},\"image\":{\"@id\":\"https:\/\/www.topfastpcb.com\/blog\/pcb-trace-width-current-capacity-guide\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-3.jpg\",\"keywords\":[\"PCB Trace Width\"],\"articleSection\":[\"News\"],\"inLanguage\":\"fi\"},{\"@type\":[\"WebPage\",\"FAQPage\"],\"@id\":\"https:\/\/www.topfastpcb.com\/blog\/pcb-trace-width-current-capacity-guide\/\",\"url\":\"https:\/\/www.topfastpcb.com\/blog\/pcb-trace-width-current-capacity-guide\/\",\"name\":\"PCB Trace Width vs Current Capacity: Design Guide for Reliable Manufacturing\",\"isPartOf\":{\"@id\":\"https:\/\/www.topfastpcb.com\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.topfastpcb.com\/blog\/pcb-trace-width-current-capacity-guide\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.topfastpcb.com\/blog\/pcb-trace-width-current-capacity-guide\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.topfastpcb.com\/wp-content\/uploads\/2026\/03\/PCB-Trace-Width-3.jpg\",\"datePublished\":\"2026-03-11T00:37:00+00:00\",\"description\":\"Learn how PCB trace width affects current capacity, heat dissipation, and reliability. 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